Diao Jinjin, Tian Yuxin, Hu Yifeng, Moon Tae Seok
Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, USA.
Department of Energy, Environmental, and Chemical Engineering, Washington University in St Louis, St Louis, MO 63130, USA; Synthetic Biology Group, J. Craig Venter Institute, La Jolla, CA 92037, USA.
Trends Biotechnol. 2025 Mar;43(3):620-646. doi: 10.1016/j.tibtech.2024.10.018. Epub 2024 Nov 23.
Poly(ethylene terephthalate) (PET) waste is of low degradability in nature, and its mismanagement threatens numerous ecosystems. To combat the accumulation of waste PET in the biosphere, PET bio-upcycling, which integrates chemical pretreatment to produce PET-derived monomers with their microbial conversion into value-added products, has shown promise. The recently discovered Rhodococcus jostii RPET strain can metabolically degrade terephthalic acid (TPA) and ethylene glycol (EG) as sole carbon sources, and it has been developed into a microbial chassis for PET upcycling. However, the scarcity of synthetic biology tools, specifically designed for this non-model microbe, limits the development of a microbial cell factory for expanding the repertoire of bioproducts from postconsumer PET. Herein, we describe the development of potent genetic tools for RPET, including two inducible and titratable expression systems for tunable gene expression, along with serine integrase-based recombinational tools (SIRT) for genome editing. Using these tools, we systematically engineered the RPET strain to ultimately establish microbial supply chains for producing multiple chemicals, including lycopene, lipids, and succinate, from postconsumer PET waste bottles, achieving the highest titer of lycopene ever reported thus far in RPET [i.e., 22.6 mg/l of lycopene, ~10 000-fold higher than that of the wild-type (WT) strain]. This work highlights the great potential of plastic upcycling as a generalizable means of sustainable production of diverse chemicals.
聚对苯二甲酸乙二酯（PET）废料在自然环境中降解性低，其管理不善对众多生态系统构成威胁。为应对生物圈中废弃PET的积累问题，PET生物升级循环利用（将化学预处理与微生物转化相结合，将PET衍生单体转化为高附加值产品）已展现出前景。最近发现的约氏红球菌RPET菌株能够以对苯二甲酸（TPA）和乙二醇（EG）作为唯一碳源进行代谢降解，并且已被开发成为用于PET升级循环利用的微生物底盘。然而，专门为这种非模式微生物设计的合成生物学工具匮乏，限制了用于拓展消费后PET生物产品种类的微生物细胞工厂的发展。在此，我们描述了针对RPET的高效遗传工具的开发，包括用于可调基因表达的两种诱导型和可滴定表达系统，以及用于基因组编辑的基于丝氨酸整合酶的重组工具（SIRT）。利用这些工具，我们对RPET菌株进行了系统工程改造，最终建立了微生物供应链，可从消费后PET废瓶中生产多种化学品，包括番茄红素、脂质和琥珀酸，实现了迄今报道的RPET中番茄红素的最高产量[即22.6毫克/升番茄红素，比野生型（WT）菌株高出约10000倍]。这项工作凸显了塑料升级循环利用作为可持续生产多种化学品的通用手段的巨大潜力。
